I had a couple people write in with the same question. I asked Gordon Strong (Zymurgy's technical editor) to take a look, and I'm sharing his response here:

"That's what was in their original recipe. Seemed short to me; my system would need at least 30 minutes at that temperature, but conversion speeds vary. I'm guessing the difference is that on professional systems, they likely achieve a much more complete grind of the grain so that the starches convert quickly. On the average homebrew system, that duration is likely too aggressive. I would extend the 154F rest to 45 minutes to be safe. The 122F rest is a protein rest; 10 minutes is fine. The mash out temp (170F) is fine. The 154F rest is the last saccharification rest, so brewers should always interpret a recipe to include the phrase "or until conversion is complete" on the last rest. That's similar to a food recipe saying "cook until done" after giving a time estimate. An iodine test can confirm, but most mashes will fully convert in 30-60 minutes at the homebrew level. So, that's a good catch, and shows a difference between what can be accomplished on a professional system vs. the average homebrew system."

Hope that helps! (And sorry I'm late to the game on this; just got back from vacation).